Integrated circuits that are formed into semiconductor substrates include multiple components such as transistors, resistors, and memory elements. These components are typically connected to one another through metal lines that are routed through multiple layers formed onto the substrate. These metal lines are often referred to as metal interconnects.
During the design phase of integrated circuits, the designer often uses a computer drafting tool to design the circuit. The next step is to design the layout of the circuit. The layout indicates how the circuit will be printed onto a substrate. During this phase of the design, it is important to understand how each of the metal interconnects will perform when carrying signals. It is particularly important to understand the behavior of signals passing through the interconnects at a wide band of frequencies. For example, it may be useful to understand the behavior of the metal interconnects at a range between 0.2 Ghz and 60 Ghz. In some cases, even higher frequencies may wish to be analyzed.
Modeling or simulation software is often used to analyze the behavior of metal interconnects before they are printed out. This allows designers to make adjustments if some aspect of the circuit does not behave as desired. Such modeling is often a time consuming and complicated process. The equations that are used to model the metal interconnects are relatively complex and thus take a lot of computing power.